LOS ANGELES – Mauricio “Shogun” Rua vs. Brandon Vera was impressive, but in a different way.

Whereas the co-main event in the UFC’s four-man title sweepstakes featured sudden, jaw-rattling violence, the main event of UFC on FOX 4 showcased the hearts of two men forced to climb a higher mountain, cardiovascularly speaking, than their counterparts.

In the end, Rua outlasted Vera, earning fourth-round TKO in the main event of UFC on FOX 4, which took place Saturday at Staples Center in Los Angeles and aired live on FOX.

Rua’s war of attrition left the audience lacking in breath, but Lyoto Machida’s co-main event knockout of Ryan Bader earned the nod from UFC president Dana White, who announced that “The Dragon” will face the winner of Jon Jones vs. Dan Henderson at UFC 151 in September.

Afterward, an exhausted Rua criticized his performance in the fight, which was scheduled for five rounds.

“I got tired from the second to the third round more than I expected,” the Brazilian light heavyweight said through a translator.

Rua could hardly be blamed, though, for relying upon his energy reserves. After trading kicks with Vera early on, Rua pulled out a surprise when he took the fight to the mat. The two then engaged in a spirited grappling exchange with Rua finishing the round with strikes from top position.

But it was the second round that quickly defined the fight as a war of attrition. Rua charged with heavy punches only to meet sneaky counters from Vera in close. Vera eluded stoppages on two separate occasions, regaining his wits after taking heavy punches. As the round wore on, both men appeared to be running low on gas.

Rua found refuge again in the clinch, where he smothered Vera in the third. But when Vera escaped, Vera landed his best combinations of the fight, smacking Rua with one-twos punctuated by stiff leg kicks.

A desperate Rua took the fight to the ground and caught his breath before landing a few glancing shots at the end of the frame.

Battered and exhausted, Rua and Vera traded blows in the fourth before Rua landed a stiff left hand that rocked Vera. Another left hook landed clean, and a one-two dropped “The Truth.” Referee Herb Dean saw enough at the 4:09 mark of the fourth round.

The win puts another classic in the bank for Rua, a former light heavyweight champ who most recently was outpointed by Henderson at UFC 139. Vera (12-6 MMA, 8-6 UFC), meanwhile, goes to 1-3 with one no-contest in his past five outings, but won’t be wanting of work after his gutsy performance.